This invention relates to forks for fork lift trucks or truck vehicles, and is directed primarily to the construction of the so-called bottom hook of a fork such as is used on these vehicles, the forks being of otherwise generally conventional form involving the shank, at the upper end of which is a top hook and the bottom hook of this invention being placed at the lower end near the heel of the fork which connects the shank with the blade and at the extremity of the blade there being the usual tip provided.
The basic improvement contemplated by this invention resides in the construction of the bottom hook and the bottom hook is arranged in order to obviate some of the problems which arise from the use of heavy forks for such fork lift trucks.
It will be readily understood that generally there are two of these forks used on each fork lift truck and while they are used in pairs, it will be obvious that the description of one will apply to the other and the advantages derived will likewise be present.
In current forks for fork lift vehicles, the upper or top hook is welded to the upper end of the shank of the fork and a bottom hook is provided which is of a form adapted to engage with the vehicle in such a manner as to maintain the entire fork in position to prevent displacement from the vehicle and at the same time permit positioning of the fork along the face of the vehicle on a carriage which is provided, in all cases that are common herein.
The prior art fails to reveal any hook arrangement such as disclosed herein, and therefore it is believed that the provision of the hook construction will materially advantage not only the rapidity with which a fork may be connected to and disconnected from a vehicle but at the same time provides certain safety factors which will be apparent as this description proceeds.
Examples of the prior art which fail to anticipate the concept, much less the structure, are the German Pat. No. 1,205,449 wherein a latch structure 7 retains an element separate from the latch itself, in position. If a knob 16 of that structure is actuated, it will not permit the fork to be removed. but only allows a separate Part 11 to be removed by sideward movement. Unless that separate action is effected by the operator, the fork cannot be removed because it is retained n front of the upstanding portion of part 7. part 11 is a loose piece and is only moved by an operator or other person, and not by the mechanism itself.
Since the German patent does not provide anticipating structure, anything shown by U.S. Pat. No. 4,482,286 of Farmer, will not provide anticipating structure either, particularly when it is noted that Farmer does not even contemplate release or connection to an L-shaped fork. Farmer shows only a pushing arrangement for material supported on a platen tongue which has no relation to an L-shaped fork as in the instant disclosure.
Other patents in the prior art such as those of Cushman U.S. Pat. No. 2,581,364, the Austrian Pat. No. 188,651 and French Pat. No. 1,168,509, while directed to fork lift Vehicle and related structure, do not contemplate a releasable latching structure such as is contemplated hereby.
It is a primary object therefore of this invention to provide a fork construction which may be in placed upon and removed from the carriage of a fork lift vehicle without the necessity for the individual who is operating the vehicle to manhandle the fork into a position which would otherwise be necessary except for the provision of the hook construction hereof.
A further object of the invention is to enable the fork to be rapidly placed upon and removed from such a carriage so that the individual who operates the same is not required to dismount from the vehicle initially to connect the fork with the vehicle nor is its subsequent manipulation of the fork required as by main force because of the arrangement of the hook which is provided hereby.